1. Field of the Invention
This invention relates to a camera of the kind using a film which is provided with a magnetic storage part and more particularly to an arrangement for recording information in the magnetic storage part.
2. Description of the Related Art
The art of magnetically recording information in a suitable part on the surface of film for cameras using silver-halide photographic films has recently been disclosed in Japanese Laid-Open Patent Application No. SHO 60-121447 and U.S. Pat. No. 4,864,332.
Two methods have been considered to be applicable for the camera of this kind in writing information in the magnetic storage part of the film. In one of the methods, a signal pattern carrying new information is recorded in the magnetic storage part of the film by means of a magnetic head after old information recorded in the magnetic storage part has been completely erased or demagnetized (or degaussed) with the magnetic head. This method requires two steps of operation including a demagnetizing step and a recording step. The other method is called an over-write method. In the over-write method, the signal pattern carrying new information is written also by means of a magnetic head in the magnetic storage part of the film in an overlapping manner without demagnetizing the old information previously recorded in the magnetic storage part. That method utilizes a feature of digital recording in which the recording is performed by plus or minus saturation in such a way as to make the intensity of recording magnetic field larger than that of the saturated magnetic field of a recording medium in use.
In cases where the information recorded in the magnetic storage part is in the form of a dense (high-frequency) signal pattern, both the above-stated two methods necessitate use of a magnetic head which has a small gap and is capable of reading precipitous changes in the signal pattern when reading out the information recorded. However, in that instance, if the information recorded in the magnetic storage part is in the form of a coarse (low-frequency) signal pattern, the magnetic head might fail to read the recorded information, because changes in the signal pattern are moderate.
Therefore, when a film developing facility assumes that the camera writes information in a dense signal pattern in the magnetic storage part of the film, and when the film developing facility is arranged to read the information written in the magnetic storage part with a magnetic head having a small gap which is designed for reading information written in a dense signal pattern from the magnetic storage part of the film, if the information is written by the camera in the magnetic storage part of the film in a coarse signal pattern, the recorded information tends to become hardly reproducible at the film developing facility.
To solve this problem, the information writing magnetic head of the camera must be arranged to be brought into close contact with the film surface for forming a dense signal pattern and also to have a small, fine gap. Such arrangement necessitates the film to be inserted and moved between a pad and the magnetic head. This, however, causes an increase in sliding resistance in feeding the film. Also, it necessitates use of some mechanism for retracting the magnetic head away from the film before inserting the film in between the magnetic head and the pad. This not only increases the size of the camera but also makes the structural arrangement of the camera complex and results in a cost increase.